The rectus sheath is formed by the aponeuroses of the internal and external abdominal oblique muscles and the transverse oblique muscle. It contains the rectus abdominus and pyrimidalis muscles. It can be divided into the anterior and posterior laminae. The arrangement of the layers of the rectus sheath is different at different points in the body. This difference is illustrated in the image below:
Johnny D's Medical Blog 
Jan 27, 2012 @ 12:08:47
The internal and external oblique muscles are labeled incorrectly. Their labels should be switched.
Feb 09, 2012 @ 10:38:54
why do you have internal oblique muscle superior to external oblique muscle?
Feb 18, 2012 @ 12:09:23
since when did internus come outside externus – this picture is incorrect and misleading
May 14, 2012 @ 22:04:35
the external oblique is superficial to the internal oblique